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Causes of Ear Infections
Middle ear infections are on the rise. The ailment, also known as otitis media, has become far more prevalent in children throughout the twentieth century, increasing 150 percent between 1975 to 1990 alone. This dramatic increase illustrates the parameters of wise antibiotic use and its abuse, while at the same time revealing the effects of breastfeeding and formula.
The middle ear is the part of the ear that is enclosed behind the eardrum. A tiny tube, called the eustachian tube, drains any fluids from the middle ear into the throat. Colds and episodes of allergic runny nose, due to airborne allergens or allergies to cow’s milk or other foods, block this eustachian tube with mucus and inflammation. When this tiny mucous-membrane-lined canal is closed off, inflammatory fluids build up in the middle ear cavity (serous otitis media), sometimes referred to as effusion. Over time, passage of nasal and throat bacteria into this tube, from pacifier use or especially when a child is lying on his back, can seed the middle ear. Bacteria can then multiply to large numbers when finding a friendly fluid-filled middle ear environment, creating painful infection (acute otitis media).
The major source of these infections is threefold: the withholding of protective mother’s milk; antibiotic treatment for mild or non-bacterial ear conditions; and inflammatory reactions to certain foods, particularly cow’s milk.
The occurrence of otitis media is 19 percent lower in breastfed infants, with 80 percent fewer prolonged episodes. The risk of otitis remains at this reduced level for four months after weaning and then increases. By 12 months after weaning, the risk is the same as in those who were never breastfed. In addition to providing general immunities to the infant, breastmilk also provides specific antibodies that prevent otitiscausing bacteria from attaching to the mucous walls of the middle ear.
Misguided Concerns About Infection
The presence of fluid in the middle ear from chronic or acute conditions reduces a child’s capacity to hear. This fluid muffles sounds but does not damage the hearing mechanism, so hearing returns once the fluid is gone. While permanent hearing damage does not occur from acute or chronic otitis, chronic interference with hearing can delay language development.
In some cases of acute infection, treated or not, the eardrum may rupture. While fear is generated around this possibility, the rupture allows the pus to drain and the middle ear to dry, most likely resolving the infection. The eardrum will then heal with some scar tissue, just as it would have after tube insertion. This scar tissue, found in many an eardrum, typically affects hearing very minimally or not at all. (Drainage from an ear can also be an outer ear infection. This is common after swimming, and the condition will respond to ear drops. Drainage from the ear for more than two days, especially when associated with hearing loss, requires prompt medical attention.)
The major concern with ear infections is that infection could develop in the mastoid air cells behind the ear. This rare condition is called mastoiditis, and is primarily of concern because of the proximity to the brain. Mastoiditis, seen as redness behind the ear and protrusion of the outer ear, can occasionally lead not only to permanent hearing loss, but to brain damage as well. Although claims are made that the incidence of mastoiditis has been greatly reduced since the introduction of antibiotics, this is not clear from a review of the literature. After the advent of antibiotics and CT scans, however, it is apparent that serious complications of acute mastoiditis have been reduced, and that the number of mastoid removals (mastoidectomies) has been reduced as well. In fact, antibiotic therapy for cases of mastoiditis appears to be valuable for preventing surgery in 86 percent of cases.
Just over half of all mastoiditis cases occur following bouts of acute otitis media. While there are other causes of mastoiditis, fewer than 4 percent of the rare deaths from mastoiditis complications occur in cases that originated as ear infections.
Some mastoiditis is blamed on poor antibiotic treatment of ear infections; other cases are blamed on antibiotic therapy itself. At the 1998 meeting of the American Academy of Otolaryngology, it was reported that serious cases of mastoiditis are rising as a direct result of strongly resistant bacteria developed through the common use of antibiotic therapy for ear infections.
Additionally, “masked mastoiditis,” in which the clearing up of the visible symptoms of the middle ear infection mask the existence of the mastoiditis, is a highly worrisome, occasionally seen condition that is directly caused by antibiotic treatment of ear infections. The behavior of the bacteria that promote this condition makes it very difficult to discover, and the condition has a high rate of dangerous complications.